Clutch for loose pulleys on sewing-machines



(No Model.)

L. A. WARREN. Clutch for Loose Pulleys on Sewing Machines.

N0- 236,656 Patented Jan. 11, 1881.

WITHEEEEE- W/EIJTUPY- #ZX y/ (JK. u@ 74 @Ntra STATES artnr Fries.

LUKE A. WARREN, OF SYOAMORE, ILLINOIS.

CLUTCH FOR LOOSE PULLEYS ON SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 236,656, dated January 11, 1881,

Application filed October 23, 1880. (No model To all lwhom fit 'may concern s Be it known that I, LUKE A. WARREN, of Sycamore, in the county of De Kalb and State of Illinois, have invented certain new and useful Improvements in a Clutch for Loose Pulleys on Sewing-Machines; and I do hereby declare the following to be a full, clear, and exact description of the invention, that will enable others skilled in the art to which it appertains to construct and make use of the same, reference being had to the accompanying drawings, and to letters and figures of reference marked thereon, forming a part of this specification.

The object of this invention is an improved clutching device attached to the loose bandpulley ot' a sewing-machine, whereby the bandpulley and fly-wheel may be run backward for the purpose of winding the bobbin, the sewing mechanism proper in the meantime remaining stationary.

This improvement relates especially to the clutching mechanism herein shown, the balance of the sewing-machine being ot' the ordinary construction.

Figure l is an outside end view of the bandpulley, showing the position of the clutching device when rotating with the main shaft; Fig. 2, a view of the same, showing the position ofthe clutch when the motion of the machine is reversed and the band-pulley is rotating loosely on the main shaft; Fig. 3, a vertical section in the plane 3 3, Fig. l; and Fig. 4, a detached detail of construction.

Referring to the drawings, A represents the band-pulley, B the main shaft, and G the arm carrying the needle-bar.

The clutch mechanism is located in the annular recess a, inclosed by the annular projectin g rim a', as shown in Fig. 3 of the drawings.

'Ihe cam-piece 5 and the collar 6 are constructed integral, and are rigidly attached to the main shaft B by means of the pin or setscrew 7.

The pawl S consists of two arms having a rigid connection with each other by means of the part 9, and is of the peculiar form shown in the drawings, Figs. 1 and 2 showing the side of the pawl, and Fig. 4 the outer edge of the same. The larger or inner ends of the pawl-arms S engage with andpass astride ot' the edge of the cam-piece 5, and are pivoted thereto. as shown in Figs. l and 2 ofthe drawings. The outer ends of the pawl-arms are loose, and are adapted to move up to or away from the inner circumferential surface of the annular recess a, in accordance with the direction in which the pulley A is rotating. The upper edges of the pawl-arms are cut away to forni the eccentric slots l0.

rEhe friction-roller 1l is of such longitudinal dimensions as to travel and rotate between the two arms forming the pawl 8, as represented by the dotted lines in Fig. l and in Fig. 3 of the drawings. The friction-roller ll is rigidly attached to the small shaft 12, the ends ot' which have bearings in the eccentric slots 10, formed in the arms of the pawl, and the periphery of the roller ll, having a frictional contact with the inner circumferential surface of the annular recess a., by which means the friction-pulley 1l is made to change its position and bearin gs from one end of the slots l0 to the other, when the motion ot the machine is reversed.

The stops 13 are inserted in the rim ct on a line passing outside of the friction-roller 1], and are intended to engage with the loose end of the outer arm of the pawl 8 when the pulley and main shaft rotate together.

One end of the spring 14 is rigidly secured to the cam 5, the opposite end being loose and bearing against the loose end of the pawl 8, and serving to force the end of the same up against the innersurface of the recess a.

rlhe annular groove l5 in the pulleyA is for the reception ofthe belt leading from the iiywheel of the machine.

The operation of this attachment is as follows: As represented in Fig. l of the drawings, one of the stops 13 is about to engage with the outer end ot' the pawl 8, the pulley turning to the left, the friction-roller ll resting in its inner bearings. The pulley now revolves with the main shaft, and the sewing mechanism is in operation. Fig. 2 shows the position ot' the friction-roller when the motion is reversed, which, as it moves up from the opposite end of the slots 10, forces the loose IOO end of the paWl away from its bearing on the inner surface of the recess a, and the pulley rotates loosely on the main shaft, which remains stationary.

This device is automatic in operation, requiring no adjustment at the hands of the operator, as it adjusts itself when the motion of the machine is reversed.

This improvement does away with the an` noyan ce and inconvenience ot' having to throw off or change the belts each time it is necessary to wind the bobbin or to reverse the 1notion of the machine for any other purpose, and all danger of breaking the thread by runnin g the machine backward is avoided.

This clutch device is not alone applicable to sewing-machines, but may be employed in connection with other mechanism requiring a clutch of this character.

IAIaving` thus described my invention, what I claim, and desire to secure by Letters Paten t, is-

1. The combination, with the loose pulley A and the main shaft B, of the cam-piece 5, the paivl 8, consisting of two arms provided with the eccentric slots 10, as described, the friction-roller 11, and the spring,r 14, substantially as herein shown and described.

2. In a clutch device of the character hereinbefore described, the combination of the following elements, consisting of the loose pulley A, the main shaft B, the cam-piece 5, the pawl S, the stops 12, the friction-roller 11, and the spring 14, all constructed, arranged, and operating` in the mannerand for the purpose set forth.

LUKE A. WARREN.

XVitnesses:

J. E. SOUTHWORTH, H. W. BACON. 

